As currently practiced, a typical technique for measuring air velocity “can be determined using a Pitot tube—with electronic output, or using a sensor of thermal dispersion—with electronic output” (US 20030205094 A1).
Regarding the measurement using Pitot tube, Klopfenstein Jr. (1998) states that: “If the Pitot tube is properly designed and the density of air passing through the Pitot tube is known, the velocity of air passing through the Pitot tube can be calculated using a standard formula”.
For example, the U.S. Pat. No. 6,711,959 B2 “Air velocity measurement instrument” consists of a Pitot tube, parallel and centered to a line adapter, and a static pressure tube. The pressure difference between the extremes of the Pitot tube and the static pressure tube represents the measure of the speed of airflow in the instrument body. This patent is oriented to measure the air velocity in places (subsystems) requiring a particular range for the speed of the airflow.
Another technical background of the invention would be a measuring air velocity device with nozzle that “includes two chambers separated by a flow nozzle. There is an entrance to the chamber upstream to the nozzle. The air handling subsystem is attached to the chamber downstream to the nozzle so that air entering the subsystem passes first through the upstream chamber, then to the nozzle, and finally to the downstream chamber before entering the subsystem. The nozzle presents an obstruction to the flow which causes a pressure difference around the obstruction. The static pressure is measured on either side of the nozzle and the measurement is calibrated to correlate the difference of static pressure with speed airflow . . . flow nozzle meters are accurate and effective for measuring flow rates. However, due to its large size, the air management subsystem must be outside.”
Sensors of thermal dispersion are another technology used for measurement of the air velocity. Specifically, and as described in the site www.tecnicasandinas.com, the thermal dispersion technology places two temperature RTD platinum thermowell protected sensors in the process line. One RTD is activated while the other senses the actual process temperature. The temperature difference between them is measured, which is directly proportional to the mass flow rate of the fluid.” The measurement of air velocity by thermal dispersion sensors directly and proportionately relates air velocity with the temperature difference.
As an alternative measurement method, U.S. Pat. No. 2,665,583 describes a thrust anemometer, which comprises a body in the form of a tetrahedron with three studs, a pivoting member which has its pivot point at the apex; the pivoting member further has an upper free end with a spherical element exposed to air currents, while its lower free end moves over a concave element with concentric circular traces, whereby it is achieved to indicate the air velocity in each circle when being deflected the pivoting member due to the drag force over the spherical body. This effect is reflected in each circumference by a light signal.
Other methods for measurement of wind velocity, are found in the use of anemometers, such as anemometers having four cups for example, where the four cups appear equidistant on a plane perpendicular to an axis where four supports of these same converge. Upon rotation, the number of turns of the axis is proportional to the wind speed. The relationship between wind speed and the cups speed is known as “anemometer factor”.
These existing techniques have several disadvantages. None is useful to measure the direction as well as the magnitude of the velocity. The Pitot tube methods principally only function with high wind-speeds, as does the use of the thrust anemometer, which must experience at minimum sufficient wind strength to impel the physical components to move. Many of these solutions also function only for measuring fluid flow in particular contexts, such as the flow of fluid within ducts, or for measurement of moderate to high wind speeds outdoors. These existing techniques have several disadvantages. None is useful to measure the direction as well as the magnitude of the velocity. The Pitot tube methods principally only function with high wind-speeds, as does the use of the thrust anemometer, which must experience at minimum sufficient wind strength to impel the physical components to move. Many of these solutions also function only for measuring fluid flow in particular contexts, such as the flow of fluid within ducts, or for measurement of moderate to high wind speeds outdoors.
The correlation between air velocity in the deviation of liquid particles can be perceived when the wind blows near a pool of water orienting water flow in a certain direction. This correlation was also reported in the document “Agricultural Tailgate Safety Training” where textually it is said that “strong winds can cause large droplets (during irrigation) to deviate from the required site.” However, although they perceive the effect, there is no precedent where it is used for measuring air velocity.